Intravascular imaging is widely used in interventional cardiology as a diagnostic tool for assessing a vessel, such as an artery, within the human body to determine the need for treatment, to guide intervention, and/or to assess its effectiveness. An imaging system such as an intravascular ultrasound (IVUS) system uses ultrasound echoes to form a cross-sectional image of the vessel of interest. Typically, IVUS imaging uses a transducer on an IVUS catheter that both emits ultrasound signals (waves) and receives the reflected ultrasound signals. The emitted ultrasound signals (often referred to as ultrasound pulses) pass easily through most tissues and blood, but they are partially reflected by discontinuities arising from tissue structures (such as the various layers of the vessel wall), red blood cells, and other features of interest. The IVUS imaging system, which is connected to the IVUS catheter by way of a patient interface module, processes the received ultrasound signals (often referred to as ultrasound echoes) to produce a cross-sectional image of the vessel where the IVUS catheter is located.
Traditionally, an IVUS run is performed when an IVUS catheter is pulled back from a blood vessel. While the IVUS catheter is being pulled back, the transducer on the IVUS catheter captures cross-sectional ultrasound images of the blood vessel at various locations of the blood vessel. These images are saved to an IVUS system and may be reviewed and analyzed by a physician later. However, the physician may not know where in the blood vessel a particular ultrasound image is taken. As such, even if the physician spots a problem on the ultrasound image, it may be difficult for him/her to perform an accurate diagnosis because the blood vessel location corresponding to the particular ultrasound image may be unavailable.
Therefore, while conventional methods and apparatuses for performing intravascular imaging are generally adequate for their intended purposes, they have not been entirely satisfactory in every aspect.